BS250
The BS250 is an P-channel MOSFET. It comes in a TO-92 package.
When you need something like the 2N7000, but as a P-channel part.
To simulate a BS250 in LTSpice, we will place an 'pmos' part and then modify its attributes to use one of our BS250.lib files.
Start by creating the following test circuit.
After you place the pmos part, control-right-click on it to bring up the part attribute editor.
Change the 'Prefix' to 'X' and the 'Value' to 'BS250'.
Make the voltage source 5V and make the resistor 1k. At this point your circuit should look like this:
Save your LTSpice circuit. Choose one of the BS250 parts (in parts/transistor/mosfet/pchannel) and drag it into the same folder. Here, I've chosen the BS250 manufactured by Philips.
Add a spice directive to load the BS250 part.
Create a transient simulation. Here, I'm simulating through 1 millisecond with a 1 microsecond time-step.
This should be your final circuit, ready to be simulated.
Run the simulation and measure the current through the 1k resistor. It should be just below 5mA.
